JP5744421B2 - Hybrid rendering apparatus and method - Google Patents

Description

  Embodiments described herein relate generally to a hybrid rendering apparatus and method for selectively applying a rendering method according to a material to be rendered, hardware performance, and the like.

  Rendering is the most basic in the computer graphics field, and various schemes for this purpose have been proposed. The most widely used rasterization method makes the most use of the hardware performance of computer graphics, but can express only direct light. In the radiosity method, light diffusion and soft shadow are skillfully expressed. However, there is a limit in expressing reflection, refraction, and the like, and a ray-tracing method. In the case of, the reflection and refraction of light is skillfully expressed, but there is a limit in expressing the diffusion and soft shadow of light.

  In order to overcome the above-described problems, the present invention is directed to a rendering apparatus and method that overcomes the limitations of existing rendering methods, improves rendering efficiency according to material characteristics, and can operate on various hardware. .

  A hybrid rendering apparatus according to an embodiment of the present invention includes a determination unit that selects a rendering method for performing three-dimensional (3D) rendering, and a first rendering that performs direct 3D rendering by directly expressing light using a first rendering method. A second rendering unit that performs the 3D rendering by expressing at least one of indirect light and shadow by a second rendering method, and a reflected light, a refracted light, and a diffracted light by a third rendering method. A third rendering unit that expresses at least one and performs the 3D rendering.

  At this time, the determination unit may select a rendering method in consideration of characteristics of a rendering target.

  The determination unit may select a rendering method in consideration of hardware performance.

  The first rendering method may be a rasterization rendering method in which vector data is converted into a pixel pattern image and rendered.

  Further, the second rendering method may be a radiosity rendering method for rendering in consideration of at least one of a light source, light between objects, and diffused light.

  In addition, the third rendering method may be a ray tracing rendering method in which a ray (ray) is traced to be reflected from a surface of an object and rendered.

  The hybrid rendering method according to an embodiment of the present invention includes a step of selecting a rendering method for performing three-dimensional (3D) rendering, a step of performing the 3D rendering by directly expressing light using a first rendering method, Performing the 3D rendering by expressing at least one of indirect light and shadow by a second rendering method; and expressing at least one of reflected light, refracted light, and diffracted light by a third rendering method. And performing the 3D rendering.

  At this time, the selecting step includes a step of selecting at least one rendering method among the first rendering method, the second rendering method, and the third rendering method, and patches and samples for radiosity rendering. The method may include adjusting the size and number of points, and adjusting the generation of a mask for ray tracing, the number of times of light reflection, and the number of times of light refraction.

  Further, the step of adjusting the mask generation, the number of times of light reflection, and the number of times of light refraction includes determining a pixel value of the mask for the ray tracing and generating the mask, and the number of times of reflection of the light and Adjusting at least one of the number of refractions of the light.

  The step of generating the mask includes setting a pixel value of a region for generating a ray (ray) to a first set value, and setting a pixel value of a region not generating a ray to a second set value. Steps may be included.

  In the present invention, by selectively applying one or more rendering methods in consideration of the characteristics of the rendering target, the advantages of each rendering method can be maximized and the rendering performance can be maximized.

  Also, by applying a rendering method in consideration of hardware performance, rendering speed and effect can be adjusted, and rendering optimized for hardware performance can be performed.

It is a figure which shows the hybrid rendering apparatus which concerns on one Embodiment of this invention. It is a figure which shows the structure of the judgment part of the hybrid rendering apparatus shown in FIG. FIG. 6 is a diagram illustrating a process of performing hybrid rendering according to another embodiment of the present invention. It is a figure for demonstrating the radiosity rendering system which concerns on one Embodiment of this invention. It is a figure for demonstrating the rasterization rendering system which concerns on one Embodiment of this invention. It is a figure for demonstrating the ray tracing rendering system which concerns on one Embodiment of this invention. FIG. 6 is a diagram illustrating a process of generating a mask for ray tracing according to an exemplary embodiment of the present invention. 5 is an operation flowchart for explaining a hybrid rendering method according to an embodiment of the present invention. FIG. 9 is an operation flowchart illustrating an embodiment of a process of selecting a rendering method illustrated in FIG. 8. 10 is an operation flowchart illustrating an embodiment of a process of adjusting the mask generation, the number of times of light reflection, and the number of times of light refraction shown in FIG. 11 is an operation flowchart illustrating an embodiment of a process for generating the mask illustrated in FIG. 10.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the contents described in the accompanying drawings. However, the present invention is not limited or limited by the embodiments. The same reference numerals provided in each drawing denote the same members.

  FIG. 1 is a diagram illustrating a hybrid rendering apparatus according to an embodiment of the present invention.

  Referring to FIG. 1, the hybrid rendering apparatus 100 includes a determination unit 110, a first rendering unit 120, a second rendering unit 130, and a third rendering unit 130.

  The determination unit 110 may select a rendering method for performing 3D rendering. At this time, the determination unit 110 may select a rendering method in consideration of the characteristics of the rendering target. For example, material information to be rendered may be extracted to check whether the material to be rendered is a material that needs reflection, refraction, or the like, or a material that needs to diffuse light. At this time, if the target object needs reflection, refraction, etc., ray tracing rendering may be performed. Radiosity rendering may be performed when light diffusion is necessary.

  In addition, a rendering method may be selected in consideration of hardware performance. For example, since the ray tracing rendering method uses a lot of hardware resources, ray tracing rendering is not performed in a hardware specification with low performance, and at least one of rasterization rendering and radiosity rendering is performed. May be. Here, the determination unit 110 will be described in more detail below with reference to FIG.

  FIG. 2 is a diagram illustrating a configuration of a determination unit of the hybrid rendering apparatus illustrated in FIG.

  Referring to FIG. 2, the determination unit 110 may include a rendering method selection unit 210, a first parameter adjustment unit 220, and a second parameter adjustment unit 230.

  The rendering method selection unit 210 may select at least one rendering method among the first rendering method, the second rendering method, and the third rendering method. That is, at least one of various rendering methods may be selected depending on the material to be rendered, the performance of hardware, and the like.

  The first parameter adjustment unit 220 may adjust the size and number of patches and sample points for radiosity rendering. That is, the speed and effect of rendering can be adjusted by adjusting the size and number of patches and sample points used to determine the color to be rendered, depending on hardware performance and input. Also, in order to determine the color between patches or sample points, patches and sample points that are close to the camera position are calculated in detail, and the amount of calculation for remote patches and sample points is reduced, resulting in a difference in image quality. It may be possible to provide a rendering performance without any problem.

  The second parameter adjustment unit 230 can adjust mask generation for ray tracing, the number of times of light reflection, and the number of times of light refraction. Here, the second parameter adjustment unit 230 may include a mask generation adjustment unit 231 and a reflection frequency adjustment unit 232.

  The mask generation adjustment unit 231 can determine a pixel value of a mask for ray tracing. Here, the mask may be for indicating a ray tracing application area. That is, since not all areas require reflection and refraction, a mask indicating areas that require reflection and refraction and areas that do not need to be generated may be generated.

  The rendering speed may be adjusted by generating a mask in consideration of the distance between the camera position and the object, the reflection / refraction coefficient, the area occupied by the object on the screen, and the like.

  The reflection frequency adjusting unit 232 can adjust at least one of the light reflection frequency and the light refraction frequency. That is, the reflection frequency adjustment unit 232 may adjust the rendering speed by adjusting the reflection and refraction frequency in consideration of hardware performance and the like.

  Referring to FIG. 1 again, the first rendering unit 120 may perform 3D rendering by directly expressing light using the first rendering method. Here, the first rendering method may be a rasterization rendering method in which vector data is converted into a pixel pattern image and rendered. At this time, the rasterization rendering method can best utilize the performance of computer graphics hardware.

  The second rendering unit 130 may perform 3D rendering by expressing at least one of indirect light and shadow by the second rendering method. Here, the second rendering method may be a radiosity rendering method for rendering in consideration of at least one of a light source, light between an object, diffused light, and shadow. At this time, the radiosity rendering method can skillfully express light diffusion and soft shadow.

  The third rendering unit 130 may perform 3D rendering by expressing at least one of reflected light, refracted light, and diffracted light by a third rendering method. Here, a ray tracing rendering method may be used in which a ray is traced and rendered along a path of reflection from the surface of the object. At this time, the ray tracing rendering method can skillfully express light reflection and refraction.

  As described above, by selecting a rendering method according to at least one of a material to be rendered and hardware performance, rendering efficiency can be maximized and efficient rendering can be performed even in various hardware environments. it can.

  FIG. 3 is a diagram illustrating a process of performing hybrid rendering according to another embodiment of the present invention.

  Referring to FIG. 3, in step 310, a scene graph that is a collection of objects constituting the screen and light information may be input as input data.

  In step 320, radiosity rendering may be performed to calculate the effect of wide-area illumination such as light diffusion or soft shadow. Here, these colors may be calculated by extracting patches or sample points from the surface of the object constituting the scene for radiosity rendering and simulating the interaction therebetween.

  In step 330, each pixel value to be rasterized and output to the screen is stored in the frame buffer using the color information of the extracted patch or sample point and the material information of the camera and the object. Also good.

  In step 340, the effect of wide-area illumination such as light reflection and refraction may be calculated by ray tracing, and the color value of the frame buffer stored in step 320 may be updated using the color value acquired by the calculation. .

  In step 350, a three-dimensional output image reflecting light reflection and refraction may be finally generated based on the updated value.

  FIG. 4 is a diagram for explaining a radiosity rendering method according to an embodiment of the present invention.

  Referring to FIG. 4, in the radiosity rendering method, not only the light from the light source but also the influence of the light exchanged with the rendering target, the diffused light, etc., all surfaces are again displayed according to the light quantity distribution. The calculation may be performed by dividing into small patches 410, 420, and 430, or by extracting sampling points on the surface. That is, all the surfaces constituting the scene are divided into patches 410, 420, 430, and how much light energy is applied from the light source to the first patch 410, from the first patch 410 to the second patch 420, and again to the third patch 430. May be calculated.

  In such a case, if the radiosity rendering method is applied to a scene composed of a large white wall surface and a red-blue base, the white wall surface can be displayed in red under the influence of diffused light reflected from the red bottom.

  FIG. 5 is a view for explaining a rasterization rendering method according to an embodiment of the present invention.

  Referring to FIG. 5, a polyhedron 520 may be formed from vertices 510 having a three-dimensional position and color, and the polyhedron may be converted 530, 540 into pixels of a graphic hardware frame buffer. On the other hand, the rasterization rendering method may be accelerated by graphic hardware, but it is difficult to express wide-area illumination such as reflection, refraction, and indirect light.

  FIG. 6 is a diagram for explaining a ray tracing rendering method according to an embodiment of the present invention.

  Referring to FIG. 6, the ray tracing rendering method means a method in which a ray (ray) is emitted in the direction of each pixel on the screen from a point in time, and an object to be seen is calculated and an illuminance of the point to be seen is calculated. At this time, the primary ray 610 emitted at the time is reflected in the case of a shadow ray 640 for calculating whether or not a shadow at the moment of hitting an object is included, in the case of a reflective surface. A reflection ray 630 for obtaining an image, a refraction ray 620 for obtaining a refracted image in the case of a refractive surface, and the like may be recursively generated. Wide ray illumination such as reflection / refraction can be expressed by the ray tracing rendering method, but it may be difficult to use for real-time rendering due to the large amount of calculation required. In addition, in order to represent light diffusion, soft shadow, and the like, the number of rays that must be used increases rapidly, and thus the amount of computation required may increase.

  FIG. 7 is a view illustrating a process of generating a mask for ray tracing according to an exemplary embodiment of the present invention.

  Referring to FIG. 7, the mask may have the same resolution as the screen and may represent an area 720 that does not require ray tracing rendering or an area 710 that does not require. As an example, ray tracing may be performed by generating a ray only for a pixel having a non-zero value in a specific area in the mask. Here, the mask generation is made up of units of objects constituting the scene, and may be generated based on the reflection and refraction coefficients of the objects.

  As an example, if the reflection and refraction coefficients of the material of the object do not exceed preset values, the pixel value in the area where the object is drawn may be set to zero. Further, when the object is farther than the predetermined value, the pixel value in the area where the object is drawn may be set to 0. Further, when the area where the object is drawn is smaller than the default value, the pixel value in the area where the object is drawn may be set to zero.

  FIG. 8 is an operation flowchart for explaining a hybrid rendering method according to an embodiment of the present invention.

  Referring to FIG. 8, in step 810, a rendering method for performing 3D rendering may be selected. As an example, a rendering method may be selected depending on the characteristics of the rendering target, hardware performance, and the like. Here, the characteristics of the rendering target may include whether the rendering target requires reflection, refraction, etc., whether indirect light needs to be expressed, or the like. Here, step 810 is described in more detail below with reference to FIG.

  FIG. 9 is an operational flowchart illustrating an embodiment of a process of selecting the rendering method illustrated in FIG.

  Referring to FIG. 9, in step 910, at least one of the first rendering method, the second rendering method, and the third rendering method may be selected. Here, the first rendering method may be a rasterization rendering method, the second rendering method may be a radiosity rendering method, and the third rendering method may be a ray tracing rendering method.

  In step 920, the size and number of patches and sample points for radiosity rendering may be adjusted. This makes it possible to calculate in detail the patches and sampling points that are close to the camera position, and to reduce the amount of calculation for patches and sampling points that are far away.

  In step 930, mask generation for ray tracing, the number of light reflections, and the number of light refractions may be adjusted. Here, step 930 will be described in more detail with reference to FIG.

  FIG. 10 is an operation flowchart illustrating an embodiment of a process of adjusting the mask generation, the number of times of light reflection, and the number of times of light refraction shown in FIG.

  Referring to FIG. 10, in step 1010, a mask may be generated by determining pixel values of a mask for ray tracing. At this time, the pixel value of the region where the ray tracing is to be performed and the pixel value of the region where the ray tracing is not performed may be set separately. The process of generating the mask will be described in detail with reference to FIG.

  FIG. 11 is an operation flowchart showing an embodiment of a process for generating the mask shown in FIG.

  Referring to FIG. 11, in step 1110, a pixel value of a region for generating a ray may be set to a first setting value. At this time, the first set value may be an arbitrary value larger than 0.

  In step 1120, the pixel value of the region where no ray is generated may be set to the second set value. At this time, the second set value may be zero.

  Therefore, the first setting value and the second setting value are values that are distinguished from each other, and it may be confirmed whether or not ray tracing rendering is necessary based on the first setting value and the second setting value when rendering is performed. .

  Referring to FIG. 10 again, in step 1020, at least one of the number of times of light reflection and the number of light refractions may be adjusted. The number of times of reflection of light and the number of times of refraction of light may be adjusted in consideration of hardware performance or the like, and the higher the hardware performance, the higher the number of times may be expressed to express an excellent stereoscopic effect.

  Referring to FIG. 8 again, in step 820, 3D rendering may be performed by directly expressing light using the first rendering method. At this time, the first rendering method may be a rasterization rendering method.

  In step 830, 3D rendering may be performed by expressing at least one of indirect light and shadow by the second rendering method. At this time, the second rendering method may be a radiosity rendering method.

  In step 840, 3D rendering may be performed by expressing at least one of reflected light, refracted light, and diffracted light by a third rendering method. At this time, the third rendering method may be a ray tracing rendering method.

  At this time, the first rendering method, the second rendering method, and the third rendering method may be selectively applied for 3D rendering.

  Embodiments of the present invention include program instructions for performing the steps of the hybrid rendering method by a computer, and further include a computer-readable recording medium including the program instructions. The recording medium may include program instructions, data files, data structures, etc. alone or in combination, and the recording medium and program instructions may be specially designed and configured for the purposes of the present invention, It may be known and usable by those skilled in the computer software art. Examples of computer-readable recording media include magnetic media such as hard disks, floppy (registered trademark) disks and magnetic tapes, optical recording media such as CD-ROMs and DVDs, and magnetic-lights such as floppy disks. A medium and a hardware device specially configured to store and execute program instructions such as ROM, RAM, flash memory, and the like are included. The recording medium is also a transmission medium such as an optical or metal line or a waveguide including a carrier wave that transmits a signal for storing program instructions, data structures, and the like. Examples of program instructions include not only machine language code generated by a compiler but also high-level language code that can be executed by a computer using an interpreter or the like. The hardware device described above is configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

As described above, the preferred embodiments of the present invention have been described with reference to the preferred embodiments of the present invention. However, those skilled in the relevant art will not depart from the spirit and scope of the present invention described in the claims. Thus, it will be understood that the present invention can be variously modified and changed. In other words, the technical scope of the present invention is determined based on the scope of claims, and is not limited by the mode for carrying out the invention.

Claims (15)

A determination unit that selects a rendering method for performing three-dimensional (3D) rendering;
A first rendering unit that directly represents light by a first rendering method and performs the 3D rendering;
A second rendering unit that performs the 3D rendering by expressing at least one of indirect light and shadow by a second rendering method, wherein a patch or a sample point is applied from a surface of an object constituting a scene. ) And simulating the interaction between the patch and the sample point;
A third rendering unit that performs the 3D rendering by expressing at least one of reflected light, refracted light, and diffracted light by a third rendering method;
The determination unit includes:
A rendering method selection unit that selects at least one of the first rendering method, the second rendering method, and the third rendering method;
A first parameter adjustment unit for adjusting the size and number of patches and sample points for radiosity rendering;
A second parameter adjustment unit for adjusting mask generation for ray tracing, the number of reflections of light, and the number of refractions of light;
Including
The second parameter adjustment unit
A mask generation adjustment unit that determines a pixel value of the mask for ray tracing, wherein the mask generation adjustment unit sets a pixel value of a region for generating a light ray to a first set value, and does not generate a light ray; A pixel rendering value is set to a second setting value .   The hybrid rendering apparatus according to claim 1, wherein the determination unit selects a rendering method in consideration of characteristics of a rendering target.   The hybrid rendering apparatus according to claim 1, wherein the determination unit selects a rendering method in consideration of hardware performance.   The hybrid rendering apparatus according to claim 1, wherein the first rendering method is a rasterization rendering method in which vector data is converted into a pixel pattern image and rendered.   The hybrid rendering apparatus according to claim 1, wherein the second rendering method is a radiosity rendering method that performs rendering in consideration of at least one of a light source, light between objects, and diffused light.   2. The hybrid rendering apparatus according to claim 1, wherein the third rendering method is a ray tracing rendering method that performs rendering by tracing a path in which light rays are reflected from the surface of an object. The second parametric adjustment unit,
The hybrid rendering device according to claim 1, further comprising a number of reflections adjustment unit for adjusting at least one of refraction times the number of reflections and the light before Symbol light. A hybrid rendering method executed by a hybrid rendering device, comprising:
Selecting a rendering scheme for performing three-dimensional (3D) rendering;
Performing the 3D rendering by directly expressing light according to a first rendering method;
The step of performing the 3D rendering by expressing at least one of indirect light and shadow by a second rendering method, and extracting a patch or a sample point from the surface of an object constituting the scene Simulating the interaction between the patch and the sample point; and
Performing the 3D rendering by expressing at least one of reflected light, refracted light, and diffracted light by a third rendering method;
And the step of selecting comprises
Selecting at least one of the first rendering scheme, the second rendering scheme, and the third rendering scheme;
Adjusting the size and number of patches and sample points for radiosity rendering;
Adjusting the mask generation for raytracing, the number of light reflections, and the number of light refractions;
Including
Adjusting the mask generation, the number of reflections of light, and the number of refractions of light includes determining a pixel value of a mask for the ray tracing to generate the mask;
Generating the mask comprises:
Setting a pixel value of a region for generating a light ray to a first set value;
Setting a pixel value of a region that does not generate a light ray to a second setting value;
A hybrid rendering method comprising: The hybrid rendering method according to claim 8 , wherein the selecting step selects a rendering method in consideration of characteristics of a rendering target. The hybrid rendering method according to claim 8 , wherein the selecting step selects a rendering method in consideration of hardware performance. The hybrid rendering method according to claim 8 , wherein the first rendering method is a rasterization rendering method in which vector data is converted into a pixel pattern image and rendered. The hybrid rendering method according to claim 8 , wherein the second rendering method is a radiosity rendering method that performs rendering in consideration of at least one of a light source, light between objects, and diffused light. 9. The hybrid rendering method according to claim 8 , wherein the third rendering method is a ray-tracing rendering method for rendering by tracing a path in which light rays are reflected from the surface of an object. Adjusting the mask generation, the number of times of light reflection, and the number of times of light refraction,
Adjusting at least one of the number of reflections of the light and the number of refractions of the light;
The hybrid rendering method according to claim 8 , further comprising: A program for causing a computer to execute the method according to any one of claims 8 to 14 .

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